Method of and apparatus for determining vacuum conditions in packaging



Jan. 14, 1964 E. ZIMMERMAN METHOD OF AND APPARATUS FOR DETERMININGVACUUM CONDITIONS IN PACKAGING 3 Sheets-Sheet 1 Filed May 16, 1961 56INVENTOR.

52772076 Zimmerman 1964 E. ZIMMERMAN 3,117,441.

. METHOD OF AND APPARATUS FOR DETERMINING VACUUM CONDITIONS IN PACKAGING3 Sheets-Sheet 2 Filed May 16. 1961 Jan. 14, 1964 E. ZIMMERMAN 3,117,441

METHOD OF AND APPARATUS FOR DETERMINING VACUUM CONDITIONS IN PACKAGINGFiled May l6, 1961 3 Sheets-Sheet 5 United States Patent F 3,117,441METHQD UP AND APPARATUS FOR DETERMIN- ENG VACUUM 0NDlTlGNS 1N PACKAGINGElmore Zimmerman, 923 Fairfield Ave, Elmhurst, lll. Filed May 16, 1961,Ser. No. 154,378 Claims. (Cl. 7337) This invention relates to packagingand in particular to vacuum sealed packaging.

It has been found that food products, such as meat, cheese and the like,may be kept fresh and Wholesome for extended periods, such as up to sixto eight weeks, at a temperature of approximately 40 F., by suitablevacuum packaging. Further, such vacuum packaging has proven efficaciousin preventing rusting of packaged ferrous elements, and in maintainingsterile conditions in sterilized packages. Machines have been developedfor vacuum packaging such products at a high rate of speed. Thesemachines have been perfected to a state wherein a high level of qualitycontrol is obtained. It has been found, however, that even with suchhighly efficient and accurate machines that the extremely low vacuumpressure condition is not always maintained in all of the packages. Morespecifically, to obtain the desired keeping qualities, the vacuumcondition must be one of approximately 10 millimeters of mercuryabsolute pressure or less. Such a package wherein the pressure is, forexample, 20 millimeters of mercury absolute pressure would appear tohave a good low pressure sealed condition while yet the packaged productin such a package would rapidly deteriorate, rust, become unsterile,etc., apparently due to the presence of the increased amount of oxygentherein.

Heretofore, the condition of the vacuum in the sealed packages has beendetermined primarily by visual inspection, reliance being placed uponthe inspectors personal skill in evaluating the condition of the vacuum.Because of the difficulty of detecting small differences in the vacuumcondition, such a method of determining the vacuum has not been found tobe fully satisfactory. Substantial economic losses may occur Where thevacuum condition is not maintained at the preselected low value, andthus t e vacuum packaging art has had a long felt need for a simple,inexpensive, yet highly accurate method of determining such vacuumconditions.

The present invention comprehends a novel method of determining thevacuum condition within a vacuum sealed package effectively solving thisserious problem.

Thus, a principal feature of the present invention is the provision of anew and improved method of determining a vacuum condition within avacuum sealed package.

Another feature of the invention is the provision of such a method fordetermining the vacuum condition within a package having a sealedflexible enclosure, comprising the steps of disposing the enclosurewithin a chamber, reducing the pressure within the chamber tosubstantially below the pressure within the package to distend theenclosure, increasing the pressure to permit a retraction of theenclosure toward the undistended arrangement, and determining thepressure within the chamllfl' when the enclosure is in a preselectedincompletely retracted arrangement.

A further feature of the invention is the provision of such a methodwherein different vacuum sealed packages are positioned seriatim to havea portion thereof at a preselected plane from which and toward which thedistention and retraction respectively are directed.

Still another feature of the invention is the provision of a new andimproved method of determining the vacuum condition within a pluralityof packages each having a sealed flexible enclosure.

3,,il'ZA i-l Patented Jan. 14, 1984 Yet another feature of the inventionis the provision of such a method including the steps of moving thepackages seriatim in a preselected path, removing a first package fromthe path, disposing the first package within a chamber, reducing thepressure within the chamber to substantially below the pressure Withinthe enclosure to distend the same, increasing the pressure to permit aretraction of the enclosure toward the undistended arrangement, anddetermining the pressure Within the chamber when the enclosure is in apreselected incompletely retracted arrangement, removing the firstpackage from the chamber removing a second package from the path,disposing the second package within the chamber, reducing the pressurewithin the chamber to substantially below the pressure within theenclosure of the second package to distend the same, increasing thepressure to permit a retraction of the enclosure of the second packagetoward the undistended arrangement, determining the pressure within thechamber when the enclosure of the second package is in a preselectedincompletely retracted arrangement, and removing the second package fromthe chamber.

Still another feature of the invention is the provision of a novelmethod of controlling delivery of a plurality of vacuum sealed packagesfrom a vacuum sealing apparatus having a preselected number of sealingstations.

A further feature of the invention is the provision of such a methodincluding the steps of selecting a first package from a first or" thestations, determining the condi tion of the vacuum in the first package,selecting an additional package from each of one or more additionalstations, determining the condition of the vacuum in each additionalpackage, and providing an indication when the vacuum condition of saidselected packages is determined to be above a preselected low pressurecondition.

Another feature of the invention is the provision of such a methodwherein said indication comprises a stopping of the apparatus.

Yet another feature of the invention is the provision of a novel methodof controlling delivery of such vacuum sealed packages for selectiveindication of the determination of a preselected number of such packageshaving an undesirable relatively high vacuum pressure condition therein.

A further feature of the invention is the provision of such a method ofcontrolling delivery of vacuum sealed packages wherein said indicationis effected when the preselected number of defective packages is ofsuccessively selected packages.

Still another feature of the invention is the provision of such a methodof controlling delivery of vacuum sealed packages wherein the defectivepackages are delivered from one station of a multi-station apparatus.

Still another feature of the invention is the provision of a new andimproved apparatus for determining the vacuum condition within a packagehaving a sealed flexi ble enclosure.

Other features and advantages of the invention will be apparent from thefollowing description taken in connection with the accompanying drawingwherein:

FIG. 1 is a perspective view of an apparatus for vacuum packagingseriatim a plurality of objects, having associated therewith anapparatus embodying the invention for determining the vacuum conditionwithin the vacuum sealed packages;

FIG. 2 is a perspective view of the apparatus for determining the vacuumcondition;

FIG. 3 is a front elevation of a portion thereof;

FIG. 4 is a front elevation thereof generally similar to FIG. 3 butillustrating the arrangement of the appa- 3 ratus upon disposition ofthe package to be tested at a preselected position in relation thereto;

FIG. 5 is a view generally similar to that of FIG. 4 but illustratingthe arrangement of the apparatus and package upon a lowering of thepressure within the surrounding chamber to a preselected value lowerthan that in the package;

FIG. 6 is a view generally similar to that of FIG. 5 but with theapparatus and package as arranged at the time of making a determinationof the pressure therein;

FIG. 7 is a fragmentary side elevation thereof with the apparatus asarranged in FIG. 3;

FIG. 8 is a fragmentary plan view thereof; and

FIG. 9 is a schematic diagram of the control circuitry thereof.

In the exemplary embodiment of the invention as disclosed in thedrawing, a vacuum sealing apparatus is shown to comprise a conventionalmachine 10 to which is delivered seriatim a plurality of objects ll,illustratively comprising meat products, to be vacuum packed in machinelit in a suitable flexible enclosure 21 to define a completed vacuumsealed package generally designated 13. As shown in FIG. 1, the objectsto be packaged, herein illustratively food products such as meatproducts, may be delivered to the machine it) by a suitable conveyor 14and the packages 13 may be delivered from the machine 10 by anothersuitable conveyor 15. In illustrating the invention, the machine ltl isshown to comprise a conventional form of such machines wherein acylindrical drum is is provided with circumferentially spaced cavities17 across which is disposed a sheet 18 of suitable heat scalable plasticmaterial and drawn into the cavity, as by application of a vacuumtherein, to receive the upwardly extending meat products 11. A similarsheet 19 of heat scalable plastic material is disposed under the meatprodnot 11 and the two sheets are heat sealed along a peripheraloutwardly projecting edge portion 20 to define the enclosure generallydesignated 21. At the time of sealing the two sheets together, a vacuumis drawn within the enclosure 21 by suitable conventional means (notshown) so that the resultant package 15 has a low vacuum pressuretherein, herein preferably no greater than approximately lO millimetersof mercury absolute pressure.

From the package forming machine 10 the packages 13 are delivered ontoconveyor 15 by suitable means such as chute Z3. Adjacent the chute 23and conveyor 15 is a vacuum determining apparatus generally designated24. Selected packages delivered from the machine 16 are removed as theyare delivered to conveyor 15 and are delivered to the vacuum determiningapparatus 24 by suitable means such as pusher 25.

Referring now more specifically to FIGURES 2 through 8, vacuumdetermining apparatus 24 includes a cabinet as having a front opening 27selectively closed by a door '28 controlled by a suitable pulleyoperator 29. When door 23 is disposed across opening 27, the chamberwithin the cabinet 26 is sealingly closed.

Within chamber St) is provided a flat support 31 carried on a pluralityof posts 32; to extend horizontally spaced above the bottom wall 33 ofthe cabinet. A table 34 is secured to the upper end of a rod 35 forvertically reciprocable movement above support 3-1 to position a package13 placed thereon with its upper surface portion 36 disposed in apreselected horizontal plane as shown in FIG. 4. The adjustment of rod35 is effected by a suitable electric motor 37 driving a worm gear 38,in turn driving a worm wheel 39 on a shaft 40 having a control arm 41connected thereto. The control arm is connected, in turn, to a link- 42connected to the control rod 35. A conventional normally closedmicro-switch 43 is secured to the support 31 by a suitable bracket 44and is actuated by an operator 45 controlled by a pin 46a as best seenin FIGS. 3 and 7. Motor 37 is secured to support 31 by a suitablebracket 44a and the gearing is similarly carried on the support 31 by apair of brackets 46.

Directly above table 34 is a small sensing button 47 having apreselected area, herein 1,276 square inches, carried at the lower endof a screw 48 adjustably threaded through a long arm 49 carrying at oneend 5%) an angle bracket 51 having an upper horizontal leg 52 pivotallyresting on a pivot 53 on an upturned end 54 of support 31. The distalend 55 of the arm 49' is provided with a threaded extension 56 on whichis mounted a pair of adjusting nuts 5'7 for adjusting the force momentof the arm assembly about pivot 53 to provide an effective downward(force on the package enclosure 21.

The angle bracket 51 includes a downturned leg 58 carrying a firstmagnet 59' on one side thereof and a pair of magnets 6% and 5% on theopposite side thereof. A first magnetic switch 61 is mounted on supportend 54 for selective actuation by magnet 59 and a pair of magneticswitches 62 and 62a is mounted on a support 63 extending from support 31for actuation by magnets and fititz, respectively. The switch 61 isarranged to be closed when the arm 49 is pivoted in a clockwisedirection to an extreme position as shown in FIG. 5. Switch 62 isarranged to open whenever the magnet fill is spaced therefrom by amovement of the arm 49 in a clockwise direction of more than 1 from itscounterclockwise ex treme posit-ion, and switch 62a is arranged to closewhen the arm 49 returns to the substantially horizontal position of FIG.6. Micro-switch '43 is arranged to open when the table 34 is lowered tois; extreme lowermost position as shown in FIG. 3.

As indicated briefly above, chamber 36 is selectively sealingly closedby door 23. As shown in FIG. 2, a conduit 64 extends through cabinet 26to communicate with chamber 30 and is connected by a suitable X-fitting65 to a first solenoid operated valve 66 for venting the corn duit 64 toatmosphere, a second solenoid operated valve 6'7 for venting slowly theconduit 64 through a small orifice 68 to the atmosphere, and a thirdsolenoid operated valve 69 for connecting the conduit 64 to a suitablevacuum pump (not shown). Also extending through the cabinet 26 is asecond conduit 79 connected through a fourth solenoid operated valve 71to a tube 72 connected to a gauge 73 indicating the absolute pressurewithin chamber 30, illustratively indicating the pressure in inches ofmercury. A panel 74 may be secured to the cabinet 26 atthe rear thereoffor carrying a plurality of relays 83, 96, 98 and 101. As shown in FIG.1, an additional control 79 may be mounted on the side of the machinelli.

Vacuum determining apparatus 24 may be utilized in dependently of apackaging machine, such as packaging machine 10, as by manual placementof selected packages therein. However, in illustrating the invention,the operation of apparatus 24 in association with machine lilto providean automatic control of the machine will be described, it beingunderstood that the functioning of the apparatus 24 is generally similarin either circumstance. More specifically, as shown in FIG. 9, theelectrical control of tie machine It? and apparatus 2 is initially bymeans of a momentarily closed switch 89 connected to one power lead L1and through a pair of normally closed timer switches 31a and 82a to arelay coil 33 connected to the other power lead L2 and a counter coil 84connected in parallel with coil 83 to lead L2. Switch 86- comprises asingle pole switch mechanically driven by thepackaging machine It) toclose once during a preselected. number of cycles of the machine it);herein the presclected number of cycles comprises the product of a wholenumber and the number of stations or cavities 17 plus or minus one. Thewhole number is merely a convenience factor which is a function of therelative speed of the machine 10 and the rate at which the apparatus 24may effect a pressure determination. Control switch may be disposedwithin control 79 and also within control 79 is provided a double poleselector switch 85 which is similarly mechanically driven by the machineto vary positions of the movable contacts 86 and 87 thereof uniquelycorresponding to each of cavity stations 17. In the illustratedembodiment the drum is provided with sixteen cavities, or stations, 17.However, to simplify the understanding of the operation, it will beassumed that the drum is provided with only two cavities which may beeffected with the drum, as shown, by suitably spacing the meat products11 prior to their delivery to the machine 19 so that only the pair ofdiametrically opposite cavities are actually employed. Where the meatproducts are delivered to the machine so that each cavit I is utilized,the operation of the machine can be determined by a simple extrapolationfrom the following description. 'Thus, assuming a convenience factor ofone, the switch 84) is arranged to close momentarily every third cycleof the machine. The closing of switch 86 energizes coil 83 which closesits associated contacts 83a to hold this circuit in after switch 80opens and at the same time the counter coil 34 is energized. As thepackage 13 drops from the chute 23, it engages a normally open switch 83which is connected through contacts 83:; to power lead L1 and to a relaycoil 89 connected to power lead L2. Relay coil 89 in turn closes itsnormally open associated contacts 895:. The closing of contacts 33a and89a energizes a solenoid valve 9% connected from power lead L2 theretothrough a set of normally closed relay contacts 91a. Solenoid valve 90operates the pusher 2S, illustratively comprising a hydraulic ram, topush the selected package 13 from the conveyor 15 into the chamber 30 ofthe apparatus 2 4.

When the selected package is positioned in place on the table 34 itcloses a normally open switch 92 carried on the rear wall of the cabinet26. The closing of switch 92 energizes a relay coil 91, thereby openingcontacts 91a associated therewith, and concurrently energizes a latchcoil 93 connected in parallel with coil 91 to power lead L2. The openingof contacts 91a tie-energizes the ram solenoid valve 91) allowing thepusher to return to its original position. At the same time, coil 91operates a second set 91b of contacts associated therewith to energizeanother solenoid valve 94 controlling the door mechanism 29 to move thedoor to a closed position across the chamber opening 27. A third set ofnormally open contacts 91c associated with coil 91 is closed by theenergization thereof to hold in the circuit to this coil.

When the door 28 closes, it operates a switch 95 to energize a relaycoil 9t: which closes an associated set of normally open contacts 9dr:to hold coil 96 energized. At the same time, the closing of switch 95energizes the solenoid valve 69. A second set of normally open con tacts96!) associated with coil 96 are closed by the energization of the coilto energize a 25-second timer 9?.

After the package 13 enters the chamber 3% and the door 28 closes thechamber 3%, an automatic elevation of the package may be effected todispose the package in the position of FIG. 4 prior to the determinationof the vacuum condition. This may be done to accommodate packages havingdifferent thicknesses, so that in each instance the movement of theplastic sheet away from the product will be from a single horizontalplane, thereby eliminating errors in the measurements as the result ofdifferent angular positions of the arm 4-9. To this end the forwardwindings F of the motor 3'7 are connected to power lead L1 through a setof normally open contacts 969 associated with coil 96 and through a setof normally closed contacts 122!) associated with coil 122. Thus, whencoil 96 is energized, the motor is automatically operated to raise thetable 34 until such time as switch 62 opens. The opening of switch 62 isadjusted so that the arm 49 will be substantially at the position ofFIG. 4 at this time.

Upon completion of the pressure determination, it is desirable to lowerthe table 34 automatically to the position of PEG. 3. This is effectedby connecting the reverse windings R of the motor 37 to the power leadL1 through normally closed contacts 83d associated with coil 83 andswitch 43 which allows the motor 37 to return the table fully toretracted position.

As discussed above, solenoid valve 69 is connected to a suitable vacuumpump (not shown) so that opening of the valve 69 effects an evacuationof chamber 30 lowering the pressure thereof. Assuming that the package13 tested has a gross leakage condition, such as caused by an incompleteseal, no seal, a channel due to a fold in the plastic sheeting, a holein the sheeting due to a cut, tear, flaw in the material or the like,the pressure within chamber 30 does not drop below the pressure withinthe package and thus the package remains in the condition of FIG. 4. Asarm 49 is not pivoted by any expansion of the package, switch 61 remainsopen, thereby maintaining coil 98 (lo-energized thereby maintainingcontacts 98a associated with coil 98 normally closed and when contacts97a are closed by operation of coil 9'7 after a twentyfive second delay,relay coil 99 is energized through normally closed contacts 93bassociated with coil 93. Energization of coil 99 closes a set ofnormally open contacts 99a associated therewith to indicate thedefective package as discussed in greater detail subsequently.

In the event that the package 13 does not have a gross leakage butmerely a minor leak, an expansion of the enclosure 21 will occur as thepressure in the chamber 39 drops. When the enclosure expand-ssufficiently to pivot the arm 49 substantially above the horizontalposition, switch 61 will be closed by the magnet 59 thereby energizingcoil 98.

Energization of coil 93 opens contacts 9811 thereby de-energizingsolenoid valve 69 and preventing further evacuation of the chamber. Atthe same time, closing of contact 61 energizes solenoid valve 67 toslowly vent the chamber through the small orifice 68. To precludede-energization of coil 98 normally open contacts 980 are associatedtherewith in parallel with switch 61.

As shown in FIG. 5, the switch 61 is not actuated until the enclosure 21is distended to become spaced substantialiy from the upper surface ltltlof the meat product 11. This assures elimination of cohesion forcesbetween the relatively sticky meat surface 100 and the plastic materialof the enclosure and assures an accurate subsequent determination of thevacuum condition. More specifically, as the vacuum pressure is slowlyreleased in chamber 30, the enclosure retracts to the position of FIG. 6wherein the arm 49 is substantially horizontal. Thus, the magnet tlacloses the switch 62a thereby energizing relay coil till. Energizationof coil 161 opens normally closed contacts ltl la associated therewithto deenergize solenoid valve 71 thereby holding the reading of thepressure on the gauge 73. It should be noted that the energization ofcoil 83 at the initiation of the operation closed its associatedcontacts 831; at that time to energize the solenoid valve 71 through thenormally closed contacts 1910.

A set of normally open contacts 1011) associated with relay coil 1191 isclosed by the energization thereof to complete the circuit to a pressureswitch 192 which is closed whenever the pressure is less thanapproximately one inch of mercury absolute. When the determined pressureis less than the pressure setting of switch 102, the closing of bothcontacts lillb and contacts 102 energizes a relay coil 1693 and aZ-second timer coil 31 in parallel. The energization of coil 193 closesnormally open contacts 193a associated therewith, thereby energizing thereset coil 165a of a stepping relay which is provided to indicate thetotal machine failures, and through selector switch 85 the reset coil196a of a stepping relay llln or the reset coil 107a of a stepping relayltll' depending on which of the two stations the package being testedwas sealed in. After two seconds the normally closed contacts 81aassociated with the two second timer coil 81 opens, therebyde-energizing coil 83 which 7 in turn effects successive deenergizatic-nof coils 191, 3? and 91.

In the event that the determined pressure is greater than the pressuresetting of the switch 1532 or switch 9% is closed as a result of thedetermination of a gross defect as discussed above, the two second timercoil 82 is energized as a result of a normally closeu switch 159remaining closed switch it}? opening only when the pressure is less thanapproximately one inch of mercury absolute). Switches P32 and iii? maycomprise a single double throw micro-switch. Thus, an alarm bell 11b isenergized and rings for two seconds. The stepping coil 1651') ofstepping relay 165 is energized concurrently with coil 8.2 and bell ilt}to advance the stepping relay res one step. Also concurrently, thecounter coil M1 is energized Depending upon the position of switcheither counter coil 112 and the stepping coil lttlb of stepping relay 1%is energized or counter coil 113 and the stepping coil 197i) of'steppingrelay 167 is energized. Whenever the step ping relay 1% or the steppingrelay 1%7 advances one step, a lower moving contact 166C or W70 of therespective relays completes a circuit to an indicating lamp 114 or 115,respectively, associated therewith to indicate that the last one, two orthree packages from that station Were defective. However, it asatisfactory package is found from that station before three successivedefective packages are found, the resetting coil ltla or 167a of therespective relay resets the relay to turn the light oil.

if any of the three stepping relays 1G5, 166 or 167 advances the fullthree steps, a relay coil 116 is energized. Enengization of relay coillid provides an indication of the successive determination of defectivepackages, herein this indication comprises an interruption of theoperation of machine 14 by suitable interruption of the electrical powerfeed thereto, thus permitting inspection of the machine to determine thecause of the continuing detects. Conjunctively or alternatively, anaudible or visual signal may be utilized. Thus, operation of the machineis automatically discontinued whenever either a preselected number ofconsecutive defective packages, herein three, are received from themachine or a preselected number of consecutive defective packages,herein three, are received from a particular station of the machine.

After two seconds, the two second timer 82 opens its normally closedcontact 82a thereby de-energizing relay coil 83 md successivelydie-energizing coils 96, 98, 101, 89 and 91 as occurs when contact 8 1aopens.

When relay coil 83 becomes de-energized, a normally closed contact dlicassociated therewith closes to energize the vent solenoid valve onallowing the pressure inside chamber 3% to quickly reach atmosphericpressure and thereby release the sealing force against the door 23. Aswitch 117 actuated by the pressure of the door when a vacuum conditionobtains in chamber 3%} is released to open thereby (re-energizingsolenoid valve 66 and energizing door valve 94 stopping the ventoperation and raising the door 28. When the door 2% is in its uppermostposition, a switch 113 closes to energize solenoid valve 119 andoperates a second pusher 2% to push the package 13 from the chamber backonto the conveyor 35. When the package -13 leaves the chamber, a switch129 closes, energizing a release coil 93 of the latching relay of whichcoil 93a comprises the latching coil. Energization of coil )3 releasesthe latching relay to permit the contacts 931) thereof to open.

To permit resetting of the latching relays by the operator when desired,a reset push button switch 1% may be provided in parallel with contacts1533a.

A pressure switch 125 may be mounted in the chamber 30 and connected inparallel with contacts to energize coil 99 in the event that thepressure drops to a preselected low value, herein substantially lowerthan approximately one inch of mercury. Thus, the various steppingrelays and indicating devices discussed above are energized and thetesting cycle stopped in a manner similar to that discussed aboverelative to the closing of contact 97a.

Thus, in brief recapitulation, the invention comprehends an improvedmethod of determining a vacuum condition within a flexible sealedpackage, such as plastic, foil, and laminated packages, tin cans, etc.,by causing a distention of the enclosure to space a preselected portionthereof from the object packaged therein and incompletely retracting thedistended enclosure to a preselected arrangement wherein the enclosureis close to but spaced from the object. The pressure determination isthen made by determining the pressure condition within the chamberwherein the package is disposed at this time. The invention furthercomprehends an improved coordinated control of a forming machine whereinautomatic testing of predetermined regular selected packages iseffected, the results of the individual determinations being coordinatedone with the other to effect an indication which as discussed above maycomprise a visual alarm, an auditory alarm, or an automaticdiscontinuation of operation of the forming machine in the event that apreselected number of consecutive defects either from the machine as awhole or from a selected station are found.

Having described my invention as related to the embodiment shown in theaccompanying drawing, it is my intention that the invention be notlimited by any of the details of description, unless otherwisespecified, but rather be construed broadly within its spirit and scopeas set out in the accompanying claims.

I claim:

1. The method of determining the vacuum condition within a packagehaving a sealed flexible enclosure, com prising the steps of: disposingthe enclosure within a chamber; reducing the pressure within the chamberto substantially below the pressure within the package to distend theenclosure; increasing the pressure to permit a retraction of theenclosure toward the undistended arrangement; and determining thepressure within the chamber when the enclosure is in a preselectedincompletely retracted arrangement.

2. The method of determining the vacuum condition within a packagehaving a sealed flexible enclosure, com prising the steps of: disposingthe enclosure within a chamber; reducing the pressure within the chamberto substantially below the pressure within the package to distend theenclosure; increasing the pressure to permit a retraction of theenclosure toward the undistended arrangement; and determining thepressure within the chamber when the enclosure has a configurationsubstantially corresponding to the configuration thereof when the pressure within and without the enclosure is atmospheric.

3. The method of determining the vacuum condition within a packagehaving a sealed flexible enclosure enveloping an object and including aportion touching the object, comprising the steps of: disposing theenclosure and enveloped object within a chamber; reducing the pressureWithin the chamber to substantially below the pressure within thepackage to distend the enclosure and thereby space said portion of theenclosure from the object; increasing the pressure to permit aretraction of the enclosure; and determining the pressure Within thechamber when said portion of the enclosure is closely juxtaposed to theobject.

4. The method of determining the vacuum condition within a packagehaving a sealed flexible enclosure, comprising the steps of: disposing te enclosure within a chamber; adjusting the position of the enclosure todispose a portion thereof at a preselected plane; reducing the pressurewithin the chamber to substantially below the pressure within thepackage to distend the enclosure and trereby move said portion beyondsaid plane; increasing the pressure to permit a retraction of theenclosure to return said portion toward said plane; and determining thepressure within the chamber when said portion is in a preselectedposition spaced from said plane.

5. The method of claim 4 wherein said plane is horizontal and saidportion is disposed at said plane by raising the enclosure.

6. The method of claim 4 wherein the pressure is maintained constant fora preselected period of time when said portion is in said preselectedposition.

7. The method of determining the vacuum condition within a plurality ofpackages each having a sealed flexible enclosure, comprising the stepsof: moving the packages seriatim in a preselected path; removing a firstpackage from the path; disposing said first package within a chamber;reducing the pressure within the chamber to substantially below thepressure within the enclosure to distend the same; increasing thepressure to permit a retraction of the enclosure toward the undistendedarrangement; and determining the pressure within the chamber when theenclosure is in a preselected incompletely retracted arrangement;removing said first package from the chamber; removing a second packagefrom the path; disposing said second package within the chamber;reducing the pressure within the chamber to substantially below thepressure within the enclosure of said second package to distend thesame; increasing the pressure to permit a retraction of the enclosure ofthe second package toward the undistended arrangement; determining thepressure within the chamber when the enclosure of the second package isin a preselected incompletely retracted arrangement; and removing saidsecond package from the chamber.

8. The method of determining the vacuum condition within a plurality ofpackages each having a sealed flexible enclosure, comprising the stepsof: moving the packages seriatim in a preselected path; removing a firstpackage from the path; disposing said first package within a chamber;reducing the pressure within the chamber to substantially below thepressure within the enclosure to distend the same; increasing thepressure to permit a retraction of the enclosure toward the undistendedarrangement; determining the pressure within the chamber when theenclosure is in a preselected incompletely retracted arrangement;removing said first package from the chamber; removing a second packagefrom the path; disposing said second package Within the chamber;reducing the pressure within the chamber to substantially below thepressure within the enclosure of said second package to distend thesame; increasing the pressure to permit a retraction of the enclosure ofthe second package toward the undistended arrangement; determining thepressure within the chamber when the enclosure of the second package isin a preselected incompletely retracted arrangement; removing saidsecond package from the chamber; removing a third package from the path;disposing said third package within the chamber; reducing the pressurewithin the chamber to substantially below the pressure within theenclosure of said third package to distend the same; increasing thepressure to permit a retraction of the enclosure of the third packagetoward the undistended arrangement; determining the pressure within thechamber when the enclo- 10 sure of the third package is in a preselectedincompletely retracted arrangement; removing said third package from thechamber; and providing an indication whenever the pressures determinedare all above a preselected pressure.

9. The method of determining the vacuum condition within a plurality ofpackages each having a sealed flexible enclosure, comprising the stepsof: moving the packages seriatim in a preselected path; removing a firstpackage from the path; disposing said first package within a chamber;reducing the pressure within the chamber to substantially below thepressure within the enclosure to distend the same; increasing thepressure to permit a retraction of the enclosure toward the undistendedarrangement; determining the pressure within the chamber when theenclosure is in a preselected incompletely retracted arrangement;removing said first package from the chamber; removing a second packagefrom the path; disposing said second package within the chamber;reducing the pres sure within the chamber to substantially below thepres sure within the enclosure of said second package to distend thesame; increasing the pressure to permit a retraction of the enclosure ofthe second package toward the undistended arrangement; determining thepressure within the chamber when the enclosure of the second package isin a preselected incompletely retracted arrangement; removing saidsecond package from the chamber; removing a third package from the path;disposing said third package within the chamber; reducing the pressurewithin the chamber to substantially below the pressure within theenclosure of said third package to distend the same; increasing thepressure to permit a retraction of the enclosure of the third packagetoward the undistended arrangement; determining the pressure within thechamber when the enclosure of the third package is in a preselectedincompletely retracted arrangement; and causing a discontinuation of themoving of said packages as a result of a determining of a pressure abovea preselected pressure in each of said chamber-pressure-determiningsteps.

10. The method of determining the vacuum condition within a packagehaving a sealed flexible enclosure, comprising the steps of: disposingthe enclosure within a chamber; reducing the pressure within the chambertoward a preselected pressure substantially below the pressure withinthe package to distend the enclosure; and stopping the reducing of thepressure at a second preselected pressure lower than the first namedpreselected pressure in the event that the enclosure does not distend toa preselected degree as a result of the reducing of the pressure.

References Cited in the file of this patent UNITED STATES PATENTS1,825,700 Landrum Oct. 6, 1931 2,737,803 Doudera et al Mar. 13, 19562,883,810 Gieskieng Apr. 28, 1959 3,027,753 Harder Apr. 3, 19623,049,978 Miles et a1 Aug. 21, 1962

1. THE METHOD OF DETERMINING THE VACUUM CONDITION WITHIN A PACKAGEHAVING A SEALED FLEXIBLE ENCLOSURE, COMPRISING THE STEPS OF: DISPOSINGTHE ENCLOSURE WITHIN A CHAMBER; REDUCING THE PRESSURE WITHIN THE CHAMBERTO SUBSTANTIALLY BELOW THE PRESSURE WITHIN THE PACKAGE TO DISTENT THEENCLOSURE; INCREASING THE PRESSURE TO PERMIT A RETRACTION OF THEENCLOSURE TOWARD THE UNDISTENDED ARRANGEMENT; AND DETERMINING THEPRESSURE WITHIN THE CHAMBER WHEN THE ENCLOSURE IS IN A PRESELECTEDINCOMPLETELY RETRACTED ARRANGEMENT.